A novel ultrasonic NDE for shrink fit welded structures using interface waves

Jaesun Lee; Junpil Park; Younho Cho

doi:10.1016/j.ultras.2016.01.009

A novel ultrasonic NDE for shrink fit welded structures using interface waves

Ultrasonics. 2016 May:68:1-7. doi: 10.1016/j.ultras.2016.01.009. Epub 2016 Feb 1.

Authors

Jaesun Lee¹, Junpil Park², Younho Cho³

Affiliations

¹ School of Mechanical Engineering, Pusan National University, Pusan 46241, South Korea.
² Graduate School, School of Mechanical Engineering, Pusan National University, Pusan 46241, South Korea.
³ School of Mechanical Engineering, Pusan National University, Pusan 46241, South Korea. Electronic address: mechcyh@pusan.ac.kr.

PMID: 26859431
DOI: 10.1016/j.ultras.2016.01.009

Abstract

Reactor vessel inspection is a critical part of safety maintenance in a nuclear power plant. The inspection of shrink fit welded structures in a reactor nozzle can be a challenging task due to the complicated geometry. Nozzle inspection using pseudo interface waves allows us to inspect the nozzle from outside of the nuclear reactor. In this study, layered concentric pipes were manufactured with perfect shrink fit conditions using stainless steel 316. The displacement distributions were calculated with boundary conditions for a shrink fit welded structure. A multi-transducer guided wave phased array system was employed to monitor the welding quality of the nozzle end at a distance from a fixed position. The complicated geometry of a shrink fit welded structure can be overcome by using the pseudo interface waves in identifying the location and size of defects. The experimental results demonstrate the feasibility of detecting weld delamination and defects.

Keywords: Nuclear power plant nozzle; Pressure vessel inspection; Pseudo interface wave; Shrink fit welded structure; Ultrasonic nondestructive evaluation.